Catskill  Water  Supply 


A  GENERAL  DESCRIPTION 


BOARD  OF  WATER  SUPPLY 
OF  THE  CITY  OF  NEW  YORK 


JUNE,  1919 


AGE 


Silver  Lake  terminal  reservoir,  in  Silver  Lake  park,  Staten  Island,  looking  south,  showing  the  North  and  South  basins  with  the  Middle  dike  and 

date-chambers  between  the  basins. 


A'fW  t/ut 


New  York’s  Catskill  Mountain 
Water  Supply 


The  Catskill  water-supply  system  is  the  largest  which  has  ever  been  undertaken. 
It  ranks  among  the  most  notable  enterprises  ever  carried  out  by  any  city,  state 
or  nation.  For  magnitude  and  cost  and  for  the  variety,  complexity  and  difficulty 
of  the  physical  problems  involved,  it  stands  with  the  great  canals,  with  the  trans¬ 
continental  railway  lines,  and  with  New  York’s  own  rapid  transit  railway  system. 
That  portion  of  this  water-supply  system  which  has  been  completed  constitutes 
about  three-quarters  of  the  whole  and  includes  the  Ashokan  reservoir,  an  artificial 
lake  12  miles  long,  in  which  are  stored  the  waters  of  Esopus  creek;  it  includes 
also  the  Catskill  aqueduct,  extending  92  miles  from  the  Ashokan  reservoir  to  the 
northern  boundary  of  the  City,  the  Kensico  storage  reservoir  near  White  Plains, 
the  Hill  View  equalizing  reservoir,  and  the  Silver  Lake  terminal  reservoir  on 
Staten  Island.  There  have  also  been  completed,  within  the  City  limits,  35  miles 
of  tunnel  and  pipe-line  which  serve  to  deliver  the  water  into  the  pipes  through 
which  it  finally  reaches  the  consumer.  In  order  to  entirely  complete  the  system, 
there  remains  the  development  of  the  Schoharie  watershed  by  the  construction  of 
the  Gilboa  dam,  which  will  form  the  Schoharie  reservoir.  From  this  reservoir 
the  water  will  be  diverted  through  the  Shandaken  tunnel,  now  under  construction, 
and  thus  find  its  way  down  the  present  channel  of  Esopus  creek  into  Ashokan 
reservoir.  About  six  years  will  be  required  for  the  completion  of  this  tunnel, 
which  is  18  miles  long. 

Water  from  the  Catskill  sources  flows  to,  and  is  delivered  within,  the  City  by 
gravity.  That  is  to  say,  the  water  flows  from  the  Ashokan  reservoir  to  the  City 
and  into  the  distribution  pipes  under  such  pressure  that  it  need  not  be  pumped  be¬ 
fore  it  reaches  the  people  who  use  it.  In  this  respect  Catskill  water  has  rendered 
unnecessary  the  pumping  which  was  formerly  done  in  Brooklyn  and  much  of  that 
in  Manhattan,  The  Bronx  and  Richmond.  The  saving  in  cost  which  has  thus  been 
effected  has  been  estimated  at-  two  million  dollars  per  year. 

Catskill  water  has  its  origin  in  the  Esopus  and  Schoharie  watersheds.  These 
watersheds,  occupying  the  central  and  eastern  portions  of  the  Catskill  mountains, 
collect  the  stream-flow  from  the  mountains  of  sparsely  populated  areas  which  they 
embrace.  The  Esopus  watershed,  draining  naturally  into  the  Hudson  river,  has  an 
area  of  257  square  miles.  The  Schoharie  watershed,  draining  to  the  north  into 
the  Mohawk  river,  has  an  area  of  314  square  miles.  The  combined  drainage  area 
of  these  two  sources  is  therefore  571  square  miles,  and  it  is  conservatively  esti¬ 
mated  that  even  during  a  series  .of  extraordinarily  dry  years,  more  than  5C0  mil¬ 
lion  gallons  of  water  daily  can  surely  be  drawn.  The  geology  of  the  areas  in 
eluded  within  the  Esopus  and  Schoharie  watersheds  is  entirely  sandstone  and  shale, 
and  the  water,  in  consequence,  is  of  an  unusual  degree  of  softness.  The  small 
population  also  results  in  a  water  free  from  pollution.  The  greater  part  of  the 
water  from  these  two  drainage  areas  will  be  stored  ,  in  the  Ashokan  reservoir,  the 
balance  being  held  in  the  Schoharie  reservoir,  the  construction  of  which  will  now 
be  undertaken. 


4 


Map  of  the  Catskill  water-supply  system  showing  its  relation  to  the  Croton  and 

Ridgewood  systems. 


The  Catskill  aqueduct,  leading  from  the  Ashokan  reservoir  to  the  City,  will, 
when  finally  completed,  have  a  capacity  of  not  less  than  500  millions  of  gallons 
per  day.  On  account  of  the  rugged  and  diversified  character  of  the  country  tra¬ 
versed  by  the  aqueduct,  several  different  types  of  construction  were  used.  Typical 
details  of  these  several  types  of  construction  are  shown  on  the  plate  printed  on 
page  20.  The  type  known  as  cut-and-cover  aqueduct  was  constructed  wherever 
the  natural  surface  of  the  ground  was  close  to  the  hight  at  which  the  water  in 
the  aqueduct  would  naturally  flow.  When  it  became  necessary  to  pierce  through 
a  mountain,  the  type  designated  as  grade  tunnel  was  used.  Where  it  was  neces 
sary  to  cross  under  a  long,  deep  valley,  such  as  that  of  the  Hudson  river,  the  type 
indicated  as  pressure  tunnel  was  used.  But  where  the  valley  was  shorter  and 
not  as  deep,  steel-pipe  siphons,  laid  just  below  the  surface  of  the  ground,  were 
employed.  For  the  supply  of  Staten  Island,  a  cast-iron  pipe  laid  in  a  trench  under 
the  bottom  of  the  river  was  employed.  This  pipe  was  made  up  of  12-foot  lengths 
with  a  flexible  joint  at  each  end. 

In  order  that  the  quality  of  the  water  delivered  should  be  of  the  very  best, 
aeration  basins,  which  consist  of  a  large  number  of  small  fountains,  have  been 
constructed  at  both  the  Ashokan  and  the  Kensico  reservoirs.  The  purpose  of 
these  fountains  is  to  throw  the  water  into  the  air  and  convert  it  into  a  fine  spray 
so  that  the  disagreeable  tastes  and  odors-  which,  at  some  seasons  of  the  year  may 
occur,  will  be  eliminated.  For  insuring  the  sanitary  quality  of  the  water  a  chlor 
inating  plant  was  installed  at  the  Kensico  reservoir  and  all  of  the  water  at  that 
point  is  sterilized  and  rendered  entirely  pure. 

The  foregoing  is  a  brief  statement  and  skeleton  •  description  of  the  Catskill 
water-supply  system  as  a  whole.  The  various  features,  including  a  brief  his¬ 
torical  statement  and  outline  of  the  organization  which  conducted  and  is  now 
carrying  on  the  work,  will  be  found  in  the  following  pages. 


THE  PERIOD  OF  PREPARATION 

Preceding  the  active  period  of  construction  there  was  necessarily  a  long  period 
of  preparation.  Passing  over  the  informal  suggestions  which  appeared  from  time 
to  time  and  which  looked  toward  the  increase  of  the  City’s  water-supply,  it  may 
be  said  that  the  final  campaign  began  with  a  report  which  was  presented  on  March 
15,  1897,  to  the  Manufacturers’  Association  of  Brooklyn,  by  a  special  committee 
of  which  Charles  N.  Chadwfick  was  Chairman.  This  Committee  had  made  an  ex¬ 
tended  investigation  of  the  problem  because  of  the  frequently  recurring  need  for 
more  water  in  that  borough.  Four  recommendations  were  made  in  this  report: 
That  all  plans  for  water  should  contemplate  a  Greater  New  York;  that  to  finance> 
the  project  the  State  Constitution  must  be  amended  so  that  the  water  debt  would 
be  separate  from  the  Constitutional  debt  limit:  that  the  project  should  be  admin¬ 
istrated  by  a  Commission  charged  from  start  to  finish  with  the  entire  responsibility 
for  the  wrork  and  that  the  City’s  needs  for  a  period  of  50  years  should  be  con¬ 
sidered. 

In  1901,  following  the  agitation  by  this  Association,  a  bill,  prepared  by  its 
Committee,  was  introduced  in  the  Legislature  having  for  its  object  the  creation 
of  a  Commission  empowered  to  add  to  the  water-supply  of  the  City.  This  bill 
failed  of  passage  and  similar  bills  were  introduced  successively  in  1902,  1903  and 
1904.  In  1898  a  consolidation  of  the  municipalities  about  the  harbor  within  Ne\f 


r> 


Ashokan  reservoir,  showing  portions  of  the  Beaver  Kill  and  Dividing  dikes,  the  Lower  and  Upper  gate-chambers,  Ashokan  bridge,  and  the  Dividing 

weir  under  the  bridge.  The  East  basin  is  in  the  background. 


York  State  was  consummated,  and  in  the  Greater  City  of  Xew  York  there  was 
united  a  population  of  3,25O,C0O.  Soon  thereafter  it  was  proposed  that  a  private 
company  should  supply  the  City  from  the  Ramapo  river  and  the  Catskill  mountains 
on  terms  which  would  have  been  very  profitable  to  the  company.  This  attempted 
exploitation  of  the  City  led  Comptroller  Bird  S.  Coler  to  have  a  thorough  investi¬ 
gation  made  and,  for  this  purpose,  he  appointed  John  R.  Freeman,  whose  report 
in  1900  set  forth  the  need  for  an  additional  supply  and  pointed  out  those  sources 
from  which  it  could  he  obtained.  The  Ramapo  scheme  being  exposed  and  the 
community  being  roused,  various  civic  organizations  became  active,  especially  the 
Merchants’  Association,  which  engaged  a  number  of  engineers  to  conduct  inde¬ 
pendent  investigations  and  whose  reports  were  published  in  August,  19C0.  Com¬ 
missioner  of  Water  Supply  Robert  Grier  Monroe,  in  December,  1902,  appointed 
William  H.  Burr,  Rudolph  Hering  and  John  R.  Freeman  as  a  Commission  on 
Additional  Water  Supply.  This  Commission  was  charged  with  the  investigation 
of  the  needs  of  the  various  boroughs  of  the  City,  of  means  for  curtailing  waste, 
and  with  the  duty  of  recommending  the  most  available  sources  and  the  best  means 
of  their  development.  This  Commission  in  November,  1903,  submitted  its  re¬ 
port,  which  recommended  the  development  of  the  Esopus  watershed  in  connection 
with  certain  sources  of  supply  lying  east  of  the  Hudson  in  Dutchess  county.  The 
following  Legislature,  however,  enacted,  laws  which  prohibited  the  City  from  uti¬ 
lizing  most  of  the  sources  east  of  the  Hudson  which  had  been  recommended  by 
the  Commission.  The  Commission  had  not  reported  favorably  on  the  filtration  of 
water  from  the  Hudson  river;  the  Aqueduct  Commissioners  were  putting  forth 
every  effort  to  develop  the  Croton  watershed  as  far  as  practicable,  and  the  De¬ 
partment  of  Water  Supply  was  doing  its  best  to  extend  the  underground  systems 
in  Nassau  county  and  in  the  immediate  background  there  was  ever  present  the 
fear  that  a  dangerous  shortage  of  water  might  at  anv  time  eventuate. 

This,  in  short,  was  the  situation  at  the  end  of  the  year  1904.  Eight  years  had 
been  spent  in  collecting  information  and  in  educating  the  people  and  the  State 
and  City  governments.  One  very  important  preliminary  step  had,  however,  been 
taken;  in  1904  an  amendment  to  the  State  Constitution  had  been  ratified,  removing 
capital  expenditures  for  water-works  from  within  the  scope  of  the  municipal  debt 
limit.  Meanwhile,  the  population  of  the  Greater  City  had  increased  to  four  mil¬ 
lions  and  was  growing  at  the  rate  of  1  IS, 000  per  year.  The  demand  for  water  was 
rapidly  going  ahead  of  the  safe  yields  of  the  supplies  available  and  severe  short¬ 
ages  had  barely  been  escaped  cn  more  than  one  occasion.  Amid  these  conditions 
the  City  again  appealed  to  the  Legislature,  and,  at  the  beginning  of  1905,  the  Mc¬ 
Clellan  Bill  was  introduced.  After  some  vicissitudes,  having  the  combined  back¬ 
ing  of  the  City  administration  and  the  civic  organizations,  this  bill  became  a  law 
by  signature  of  Governor  Higgins,  on  June  3,  1905. 

In  order  to  safeguard  the  interests  of  all  communities  of  the  State  and  to 
control  the  utilization  of  the  State’s  water  resources,  the  Legislature  coincidentally 
passed  a  companion  bill  creating  a  State  Water  Supply  Commission.  These  bills, 
.approved  on  the  same  day,  became,  respectively,  Chapters  724  and  723  of  the 
Laws  of  1905.  From  time  to  time,  as  the  years  passed,  these  laws  were  amended 
and  other  special  legislation  was  enacted.  The  duties  of  the  State  Water  Supply 
Commission  were  merged  with  those  of  the  State  Conservation  Commission.  New 
York  City  was  required  to  create  and  maintain  a  special  force  of  constabulary  for 
the  protection  of  the  communities  in  which  its  construction  operations  were  being 


8 


z>dJ  wtoajpumoQ 


'ross-sections  of  the  masonry  dams  of  the  Catskill  water-supply  system.  Flood  waters  will  flow  over  the  top  of  the  Gilboa  dam  but  not  over 

4-u  «  r> a —  ~ ..  is  a  „ 


9 


carried  on.  Certain  municipalities  were  given  rights  to  take  water  from  the  new 
aqueduct.  Labor  laws  were  made  more  drastic  and  statutes  relating  to  the  lia¬ 
bility  of  employers  were  enacted.  Payment  for  indirect  damage  to  land  and 
property  not  actually  taken  for  the  needs  of  the  water-supply  and  for  the  loss  of 
business  and  wages  was  provided  for.  Under  these  various  prescriptions  and  re¬ 
quirements  the  work  was  rapidly  and  energetically  prosecuted  so  that  by  the  end 
of  1917  the  first  step  in  the  development  as  a  whole  was  completed  and  250  mil¬ 
lions  of  gallons  of  Catskill  water  were  daily  available  for  use.  Since  that  time  the 
system  has  in  fact  been  drawn  upon  for  an  average  of  more  than  400  million  gallons 
daily. 


THE  ORGANIZATION 

i 

The  law  provided  that  the  three  commissioners  of  the  Board  of  Water  Supply 
should  be  appointed  by  the  Mayor  and  should  be  removable  only  “for  incompet¬ 
ency,  or  misconduct  shown  after  a  hearing,  upon  due  notice,  upon  stated  charges. 
*  *  In  this  manner  continuity  of  administration  and  policy  in  the  prosecution 
of  the  undertaking  was  assured.  On  June  9,  1905.  Mayor  George  B.  McClellan 
appointed  as  members  of  the  Board  of  Water  Supply,  J.  Edward  Simmons,  who 
was  elected  President,  Charles  N.  Chadwick  and  Charles  A.  Shaw.  Upon  the 
resignation  of  Mr.  Simmons,  Mayor  McClellan  appointed  John  A.  Bensel,  who 
was  elected  President  on  January  31,  1908.  Mr.  Bensel’s  resignation,  at  the  end 
of  1910,  was  followed  by  the  appointment  by  Mayor  William  J.  Gaynor  of  Charles 
Strauss,  who  was  elected  President,  February  8,  1911.  Mr.  Shaw  resigned  on 
January  12,  1911,  and  his  place  was  filled  by  the  appointment  of  John  F.  Galvin  on 
January  23,  1911.  Mr.  Strauss  resigned  March  19,  1918,  and  Mayor  John  F.  Hylan 
appointed  L.  J.  O’Reilly  to  the  vacancy  on  April  23,  1918,  on  which  day  Mr.  Galvin 
was  elected  as  President  of  the  Board.  At  this  time  the  Commission  is  therefore 
constituted  as  follows:  John  F.  Galvin,  President;  Charles  N.  Chadwick  and  L. 
J.  O’Reilly. 

It  was  realized  at  the  very  beginning  that  there  were  certain  fundamental  poli¬ 
cies  to  be  determined  upon.  They  were :  Unity  of  organization,  thoroughness, 
efficiency,  economy,  continuity  of  plan,  and  speed.  These  principles  were  worked 
out,  and  exactly  four  months  after  its  appointment,  on  October  9,  1905,  the  Board 
of  Water  Supply  submitted  to  the  Board  of  Estimate  and  Apportionment  for  its 
approval  a  map,  plan  and  estimate  of  cost  as  a  complete  project  for  obtaining 
water  from  the  Catskill  mountains,  setting  a  standard  of  speed  which  has  been 
continuously  maintained. 

The  functions  of  the  Board  were  executed  through  several  bureaus,  the  head 
of  each  of  which  reported  directly  to  the  Commissioners.  The  Administration 
bureau  was  headed  by  the  Secretary,  the  present  incumbent  being  Benjamin  F. 
Einbigler.  This  bureau  had  charge  of  the  official  records,  accounts,  purchasing  of 
supplies,  and  of  other  matters  of  general  administration.  H.  C.  Buncke  has  been 
Auditor  of  the  Board  since  its  organization.  The  Real  Estate  bureau  was  charged 
with  the  acquisition  of  property  by  direct  purchase,  with  the  adjustment  and 
payment  of  taxes  on  property  acquired  by  the  Board,  and  with  all  similar  related 
matters.  The  lands  necessary  for  the  purposes  of  the  reservoirs  and  aqueducts 
were  secured  through  condemnation  proceedings,  as  provided  in  the  statute.  In 


10 


With  nearly  25,000  laborers  in  camps  during  construction,  the  Aqueduct  Police  protected  com¬ 
munities  near  the  water-works.  Their  presence  alone  was  a  deterrent  to  those  criminally 
inclined.  They  maintained  order,  protected  person  and  property  and  enforced  sanitary  and 
other  rules,  as  well  as  local  ordinances  and  laws  governing  intoxicants,  concealed  weapons, 
speeding,  etc. 


11 


these  proceedings  the  City  was  represented  by  the  Corporation  Counsel  and  by 
special  counsel  appointed  by  him. 

To  the  Police  bureau,  now  under  the  direction  of  Commissioner  Galvin,  was 
assigned  the  protection  of  “the  inhabitants  of  the  localities  in  which  any  work 
may  be  constructed  under  the  authority  of  this  act  and  during  the  period  of  con¬ 
struction,  against  the  acts  or  omissions  of  persons  employed  on  such  works  or 
found  in  the  neighborhood  thereof.” 

The  Bureau  of  Claims,  of  which  John  H.  McManus  is  now  Chief,  was  charged 
with  the  duty  of  collecting  facts  relating  to  claims  for  indirect  damage,  claims 
for  damage  to  established  business  arising  from  the  creation  of  the  new  water 
system,  and  many  other  closely  related  matters.  This  bureau  cooperates  with  the 
Corporation  Counsel  in  the  investigation  and  preparation  of  cases  prior  to  their 
trial  before  the  Commissioners  of  Appraisal. 

During  the  summer  of  1905,  John  R.  Freeman,  William  H.  Burr  and  Frederic 
P.  Stearns  were  appointed  Consulting  Engineers  and  J.  Waldo  Smith  was  placed 
in  charge  of  the  Engineering  bureau  as  Chief  Engineer.  To  this  bureau  was  com¬ 
mitted  the  duty  of  making  all  surveys  and  investigations,  the  preparation  of  esti¬ 
mates,  designs,  contracts  and  reports,  the  inspection  and  test  of  supplies,  equipment 
and  materials,  the  supervision  of  construction  and  of  all  other  engineering  matters 
relating  to  the  project  as  a  whole.  This  bureau  was  divided  into  departments, 
which  were  again  divided  into  divisions  and  sections,  the  department  engineers 
reporting  directly  to  the  Chief  Engineer.  Each  department  was  divided  into  from 
four  to  six  divisions,  each  division  having  supervision  of  construction  work  amount¬ 
ing  in  value  to  from  five  to  nine  millions  of  dollars. 

The  work  of  the  Board  of  Water  Supply  is  being  done  under  the  8-hour  law. 
From  the  beginning,  the  problems  of  sanitation,  of  contentment  and  of  efficiency 
on  the  part  of  all  workers  were  considered.  Contracts  along  these  lines  were 
carefully  drawn.  Camp  schools  to  teach  the  English  language  to  the  wrorkingmen 
were  established,  and  through  the  medium  of  a  common  language  misunderstand¬ 
ings  were  removed.  The  human  side  of  the  workingman  was  considered.  There 
were  no  strikes  and  the  death  rate  from  ail  causes  was  less  than  one-half  that  of 
the  corresponding  rate  in  New  York  City.  In  addition  to  this,  each  individual 
in  all  departments  of  the  work  has  recognized  a  certain  freedom  which  has  stim¬ 
ulated  him  to  take  the  initiative  in  the  work  of  his  particular  department  with  a 
sense  of  responsibility  and  with  energy,  faithfulness  and  efficiency  for  the  good 
of  the  whole,  the  result  of  which  has  developed  the  wonderful  esprit  de  corps  of 
the  organization. 


CONTRACTS 

The  Board  is  required  by  law  to  do  practically  all  the  construction  by  contracts 
based  on  bids  received  after  public  advertisement.  The  work  was  divided  into  a 
number  of  parts,  mainly  along  geographical  lines,  and  contracts  were  entered  into 
with  companies  who  were  familiar  with  the  class  of  work  involved,  to  perform  the 
actual  construction  and  furnish  such  necessary  materials  as  were  not  found  on 
the  site  of  the  work.  There  have  been  24  major  contracts,  each  amounting  to 
between  one  and  twelve  million  dollars ;  40  amounting  to  between  $100,000  and 
$1,000,000;  while  74  minor  contracts  have  been  let. 

During  the  years  of  active  construction  the  contractors’  daily  forces  ranged 
from  a  minimum  of  5C0  to  a  maximum  of  17,243,  counting  only  the  men  actually 


12 


Contractors’  Camps — (1)  Outdoor  stoves  at  Camp  Hill  View.  (2)  Chadwick  avenue  at 
“Camp  City”,  at  Ashokan.  (3)  Mess  hall,  Camp  Hill  View.  (4)  Camp  Rlakeslee  near 
Croton  lake.  (5)  Operating  room  in  contractor's  hospital.  (6)  Recreation  at  close  of  legal 
8-hour  day. 


and  directly  at  work  on  the  City’s  structures.  If  the  large  number  of  men  in 
the  cement  mills,  metal  and  other  manufactories,  scattered  throughout  the  coun¬ 
try  producing  materials  which  were  directly  used  in  the  construction  work  are 
included,  the  daily  force  would  have  totaled  a  maximum  of  about  25,000. 


THE  ESOPUS  DEVELOPMENT 
The  Ashokax  Reservoir 

The  Ashokan  reservoir  is  located  in  Ulster  county,  about  14  miles  west  from 
the  City  of  Kingston.  Its  cost,  together  with  that  of  the  necessary  appurtenant 
works,  including  the  relocation  of  highways  and  of  the  Ulster  and  Delaware  rail¬ 
road,  was  nearly  $20,000,000.  This  reservoir  has  a  water  surface  of  8,180  acres 
and  an  available  capacity  of  128  billions  of  gallons,  a  quantity  sufficiently  great  to 
cover  all  of  Manhattan  Island  to  a  depth  of  30  feet,  its  area  being  equivalent  to 
that  of  Manhattan  below  110th  street.  The  principal  structures  which  form  this 
reservoir  are  the  Olive  Bridge  dam,  built  of  masonry,  across  the  Esopus  creek, 
the  earthen  dikes  or  dams  which  close  in  the  gaps  between  the  hills  forming  the 
natural  walls  of  the  reservoir,  the  Dividing  dike  and  weir,  which  separates  the 
reservoir  into  two  basins,  and  the  Waste  weir,  over  which  the  surplus  flood  waters 
may  be  safely  discharged.  The  Ashokan  reservoir  is  divided  into  two  parts,  which 
are  known  as  the  East  basin  and  the  West  basin,  the  full  water  surface  elevation 
of  the  West  basin  being  at  590  feet  above  mean  tide  at  New  York,  while  the  East 
basin  is  at  an  elevation  3  feet  lower.  This  division  into  two  basins  was  made 
so  as  to  provide  greater  flexibility  of  operation  and  thus  at  all  times  insure  the 
drawing  of  water  from  that  part  of  the  reservoir  in  which  the  conditions  are  the 
most  favorable. 

The  masonr)'  portion  of  the  Olive  Bridge  dam  is  founded  on  solid  ledge-rock 
and  was  built  of  Cyclopean  concrete  faced  with  smoothly  finished  concrete  blocks. 
At  each  end  the  masonry  section  is  flanked  by  earthen  dikes  built  of  selected  earth 
which  was  spread  in  thin  layers  and  thoroughly  compacted  by  rolling.  The  bot¬ 
toms  and  slopes  of  the  reservoir  basins  were  cleared  of  trees,  brush  and  all  other 
objectionable  matter  ;  40  miles  of  new  highway  were  constructed  around  the  reser¬ 
voir.  This  work  required  the  construction  of  ten  new  bridges,  one  of  which  has 
a  span  200  feet  long  and  one  of  which  has  a  total  length  of  1,120  feet.  The  re¬ 
location  of  the  Ulster  and  Delaware  railroad  required  the  construction  of  11  miles 
of  new  road-bed  and  track. 

The  work  on  the  Ashokan  reservoir  required  the  services  of  an  army  of 
laborers,  which  force  attained  a  maximum  of  3.000  men,  who  lived,  many  of  them 
with  their  families,  in  a  camp  near  the  work.  In  order  to  serve  a  community 
thus  formed,  sewerage  and  water-supply  systems  were  constructed,  streets  built, 
electric  lights  and  telephones  furnished:  National  and  savings  banks  were  estab¬ 
lished,  a  hospital  w’as  provided,  and  police  and  lire  protection  were  furnished; 
schools  for  children  and  for  the  men  on  the  work  were  established  and  quarters  for 
the  holding  of  divine  service  and  for  a  Y.  M.  C.  A.  were  provided.  The  maximum 
population  in  the  main  camp  was  approximately  4.500.  On  the  completion  of  the 
work  the  camp  was  so  thoroughly  removed  that  scarcely  a  trace  of  it  can  now’’ 
be  found.  In  connection  with  the  construction  of  the  Ashokan  reservoir  there 


14 


A  group  of  highway  bridges,  all  of  reinforced  concrete.  (1)  Esopus  bridge  across  the  creek 
just  above  the  westerly  end  of  the  reservoir;  five  spans,  67^4  feet.  (3  and  5)  Spillway 
bridge,  175-foot  span,  across  the  Waste  channel  through  which  flood  waters  are  discharged 
which  pass  over  the  Waste  weir  of  the  Ashokan  reservoir.  (2)  Traver  Hollow  bridge 
over  a  small  stream  entering  the  West  basin  of  the  Ashokan  reservoir;  a  200-foot, 
3-hinged  arch.  (4)  Ashokan  bridge  crossing  the  reservoir  between  the  East  and  West 
Basins;  15  spans  of  671, 4  feet.  (6)  Rye  Outlet  bridge  across  the  Kensico  reservoir;  five 
spans  of  127  feet. 


15 


were  built  approximately  30  miles  of  railroad  on  which  were  operated  33  loco¬ 
motives  and  580  cars.  Other  plant  used  included  60  derricks,  7  cableways,  16 
steam  rollers,  19  steam  shovels,  besides  the  concrete  mixing  outfits,  the  air-com¬ 
pressor  plants,  the  machine-shops,  and  the  many  other  items  necessary  for  the 
production  of  a  completed  piece  of  work. 

The  Kensico  Reservoir 

The  Kensico  reservoir,  in  Westchester  county,  30  miles  north  from  the  City 
Hall,  was  designed  to  contain  sufficient  Catskill  water  for  maintaining  the  supply 
over  a  period  of  several  months.  It  serves  as  a  storage  reservoir,  so  that  the  flow 
to  the  City  will  not  be  interrupted  while  the  75  miles  of  aqueduct  between  it  and 
the  Ashokan  reservoir  are  at  any  time  out  of  service.  This  reservoir  is  formed 
by  the  Kensico  dam,  across  the  valley  of  the  Bronx  river,  about  three  miles  north 
of  White  Plains  and  15  miles  north  of  the  Hill  View  reservoir.  Its  capacity  is  29 
billions  of  gallons,  and  its  surface  elevation  is  at  355  feet  above  mean  tide  at 
New  York.  The  area  of  its  water  surface  is  2,218  acres  and  the  marginal  protec¬ 
tive  strip  around  its  entire  circumference  is  in  few  places  less  than  500  feet  wide. 
The  Kensico  dam  is  one  of  the  great  masonry  structures  of  the  world.  It  con¬ 
tains  altogether  nearly  one  million  cubic  yards  of  masonry — about  one-third  that 
which  the  Egyptians  placed  in  the  great  pyramid.  However,  of  the  large  amount 
of  masonry  in  this  dam  only  about  one-third  is  visible  above  the  surface  of  the 
ground.  At  the  point  of  greatest  hight  it  rises  307  feet  above  the  rock  founda¬ 
tion  on  which  it  rests.  A  new  highway  system,  rendered  necessary  by  the  con¬ 
struction  of  the  Kensico  reservoir,  embraced  the  construction  of  15  miles  of  road 
on  which  were  a  number  of  bridges,  one  of  them  a  reinforced-concrete  structure 
of  five  arches,  each  about  127  feet  long.  This  bridge  carries  the  highway  over 
an  arm  of  the  reservoir  and  the  roadway  at  the  center  is  107  feet  above  the  reservoir 
bottom. 

Catskill  water  enters  the  Kensico  reservoir  near  its  upper  end  and  is  drawn 
from  the  lower  end  through  a  system  of  gates  located  in  chambers  about  one  mile 
north  from  the  Kensico  dam.  At  this  point  provision  is  made  for  controlling  the 
rate  at  which  the  water  is  drawn,  for  screening  and  for  sterilizing  it  with  liquid 
chlorine.  Here  also  has  been  provided  a  large  aeration  basin  in  which  the  water  is 
thrown  into  the  air  through  1,599  nozzles.  This  operation  results  in  thoroughly 
mixing  the  water  with  air  and  thus  aiding  its  purification. 

The  Kensico  dam  is  located  practically  on  the  site  of  a  small  original  dam 
which  formed  the  old  Kensico  reservoir  in  which  were  stored  the  waters  of  the 
Bronx  and  Byram  rivers.  This  old  reservoir  was  very  much  smaller  and  lower 
than  the  present  one  and  it  has  been  entirely  obliterated.  The  Kensico  dam  is  a 
gravity  masonry  structure  built  of  Cyclopean  masonry  faced  on  its  up-stream  side 
with  concrete  blocks  and  with  granite  masonry  on  its  down-stream  face.  In  order 
to  provide  for  the  movements  which  result  from  seasonal  changes  of  temperature, 
the  dam  is  divided  into  sections  by  expansion-joints  spaced  about  80  feet  apart. 

The  accompanying  photographs  indicate  the  architectural  treatment  which  was 
developed  on  the  down-stream  face  of  the  dam.  Local  stone  was  used  for  the 
facing  of  the  dam  and  an  effort  was  made  to  secure  as  rough  and  rugged  an  ap¬ 
pearance  as  was  consistent  with  the  principles  of  the  adopted  design. 

Preliminary  surveys  for  the  Kensico  reservoir  were  begun  in  May,  1906,  and 
the  contract  for  the  construction  of  the  dam  was  awarded  in  December,  19C9.  the 
amount  of  the  contract  being  $8,006,300.  It  was  required  that  the  work  should 


16 


Kensico  clam  and  portion  of  the  reservoir,  with  the  Lower  Lflluent  chamber  in  right-  background, 


17 


be  entirely  completed  by  February,  1920.  Due.  however,  to  the  exceptional  manner 
in  which  the  work  was  prosecuted,  the  dam  was  completed  to  its  full  hight  nearly 
four  years  sooner  than  was  thought  possible  when  the  contract  was  prepared.  The 
maximum  number  of  employees  on  the  work  was  about  1,500.  These  men  lived, 
many  of  them  with  their  families,  in  a  camp  below  the  site  of  the  dam.  This  camp 
wras  provided  with  sewerage  and  water-supply  systems,  and  the  best  of  care  was 
taken  of  the  sanitary  situation.  Schools  for  children  and  men  were  provided  and 
a  hospital  was  established. 

Power  necessary  for  the  varied  operations  entering  into  the  construction  and 
execution  of  the  work  was  transmitted  from  power-houses  of  The  New  York 
Edison  Company,  in  New  York  City,  over  a  transmission-line  constructed  especial¬ 
ly  for  this  purpose. 

The  total  volume  of  masonry  in  the  dam  is  965.CC0  cubic  yards.  The  maximum 
amount  placed  in  one  month  reached  84.450  cubic  yards  in  August.  1914,  while  in 
the  season  of  approximately  eight  working  months  485.C00  cubic  yards  were  put  in 
place.  There  were  used  in  the  dam  897,000  barrels  of  Portland  cement. 

The  Hill  View  Reservoir 

The  Hill  View,  reservoir  is  located  on  the  highest  available  ground  in  the  City 
of  Yonkers,  just  north  of  the  New  York  City  line,  and  15  miles  south  of  Kensico 
reservoir.  It  is  an  uncovered  artificial  reservoir  of  the  earth  embankment  type, 
and  is  lined  with  concrete.  It  has  a  depth  of  36 Yz  feet  and  a  water-surface  area  of 
90  acres.  It  holds  900  million  gallons,  its  function  being  to  equalize  the  difference 
between  the  use  of  water  in  the  City,  as  it  varies  from  hour  to  hour  throughout 
the  day,  and  the  steady  flow'  in  the  aqueduct.  Its  outlet  is  the  vertical  Dowmtake 
shaft  of  the  single  large  distribution  tunnel  which  goes  under  The  Bronx  and 
Manhattan  to  Brooklyn  and  the  pressure  of  the  water  delivered  to  the  City 
through  that  tunnel  is  due  to  the  great  elevation,  295  feet  above  sea-level,  of  the 
water  surface  in  Hill  View  reservoir.  The  Catskill  water  is  delivered  to  the  City, 
therefore,  161  feet  higher  than  Croton  water.  The  reservoir  is  divided  into  two 
basins  by  a  wall  2,740  feet  long  that  conlains  the  by-pass  aqueduct,  so  that  either 
one  or  two  basins  may  be  used,  or  be  by-passed  whenever  required,  directly  into 
the  City  tunnel.  The  contract  for  its  construction,  including  some  tunnel  work, 
was  awarded  in  December,  1909.  It  wras  first  filled  December  29,  1915,  the  cost  of 
the  completed  work  being  $3,212,900. 

The  Silver  Lake  Reservoir 

This  small  distribution  reservoir  for  Staten  Island  is  about  2,400  feet  long 
by  1,500  feet  wide,  uncovered  and  formed  by  the  natural  ground  and  by  artificial 
embankments  with  core-walls.  It  is  not  lined  with  concrete.  A  dividing  dike 
paved  with  concrete  divides  the  reservoir  into  two  basins,  holding  together  435 
million  gallons.  From  a  gate-chamber  built  in  this  dike,  reinforced-concrcte  con¬ 
duits  extend  to  the  boundary  of  the  reservoir,  and  cast-iron  pipes  connect  these 
with  the  Narrows  siphon  and  with  the  Staten  Island  service  mains.  It  has  a  depth 
of  35  feet  and  the  water  surface  is  228  feet  above  sea-level. 


18 


dam,  the  Pool  and  the  Cascade  basing. 


19 


The  Aqueduct 

As  has  been  pointed  out,  four  distinct  types  of  conduit  or  aqueduct  were 
adopted  to  meet  the  varying  physiographic  features  of  the  country  traversed  by 
the  aqueduct  from  the  Catskill  mountains  to  the  City.  \\  here  the  topography  and 
the  elevation  of-  the  ground  permitted  the  cut-and-cover  type  was  used.  This 
type  was  the  least  expensive,  and  was  built  for  a  total  of  55  miles.  The  construc¬ 
tion  consisted  of  excavating  a  trench,  in  the  bottom  of  which  a  floor  or  invert  of 
concrete  was  placed.  Resting  upon  the  sides  of  the  invert  and  bonded  to  it,  the 
side-walls  and  arch  of  concrete,  without  steel  reinforcement,  were  poured  be¬ 
tween  steel  forms,  to  the  desired  horseshoe  shape.  From  outside  to  outside  of 
the  masonry  required  a  trench  28  feet  wide  or  about  as  wide  as  between  curb  to 
curb  of  a  New  York  cross-town  street.  Sufficient  earth  was  taken  from  the 
trench  to  form  a  protective  grassed  covering  of  at  least  three  feet  over  the  con¬ 
crete.  That  portion  north  of  Kensico  reservoir  is  17  feet  high  and  17  feet  6  inches 
wide,  inside  dimensions,  and  has  generally  a  slope  of  about  1.1  feet  per  mile, 
which  is  sufficient  to  allow  the  desired  flow  of  water  to  pass  by,  nearly  although 
not  completely,  filling  the  aqueduct.  Between  Kensico  and  Hill  View  reservoirs 
the  cross-section  was  enlarged  to  a  hight  of  17  feet  6  inches  and  a  width  of  18 
feet. 

Where  hills  or  mountains  were  encountered,  and  it  would  have  been  imprac¬ 
ticable  or  uneconomical  to  circumvent  them,  tunnels  were  driven  and  lined 
throughout  with  concrete  without  steel  reinforcement.  This,  the  grade-tunnel  type, 
acts  similarly  to  the  cut-and-cover  type,  in  that  the  water  flows  in  it  as  it  would  in 
an  open  channel.  It,  also,  is  a  horseshoe  shape,  but  of  lesser  dimensions  and 
steeper  slopes.  There  are  24  of  these  grade  tunnels,  aggregating  14  miles ;  they 
are  17  feet  high  and  13  feet,  4  inches  wide  inside. 

Where  valleys  were  encountered,  it  was  not  possible  to  carry  the  aqueduct 
along  at  the  natural  elevation  or  gradient  which  the  water  would  take,  and  in 
such  cases  types  .were  adopted  which  would  withstand  the  bursting  pressure  pro¬ 
duced  by  placing  the  aqueduct  below  the  hydraulic  gradient.  In  the  larger  valleys 
the  pressure-tunnel  type  was  used,  which  consisted  of  a  circular  tunnel  driven  deep 
enough  below  the  valley  bed  so  that  the  rock  would  withstand  the  bursting  pres¬ 
sure.  The  tunnel  is  connected  at  either  end  to  the  aqueduct  by  vertical  circular 
shafts  also  in  suitable  rock.  Tunnels  and  shafts  are  lined  with  concrete  without 
steel  reinforcement  throughout  and  all  seams  around  the  concrete  and  in  the  rock 
filled  by  forcing  in  under  pressure  thin  grout  made  of  Portland  cement,  fine  sand 
and  water.  Drainage  shafts  were  constructed  so  that  each  pressure  tunnel  can 
be  unwatered  for  inspection,  cleaning  and  repair.  Besides  the  end  and  drainage 
shafts  other  shafts  were  sunk  to  aid  in  excavating  and  lining  the  tunnels.  These 

construction  shafts  were  afterwards  sealed  with  deep  concrete  plugs  just  above 

the  tunnel  and  partially  refilled,  near  the  top,  with  rock  debris  and  earth  supported 

on  concrete  arches  across  the  shaft.  There  are  seven  of  these  pressure  tunnels, 

totaling  17  miles,  varying  in  diameter  from  14  feet  to  16  feet,  7  inches. 

The  most  important  of  the  valleys  to  be  crossed  was  that  of  the  Hudson  river, 
where  the  tunnel  was  driven  in  granitic  rock  at  a  depth  of  1,114  feet  below  sea- 
level.  This  14-foot  tunnel  extends  from  a  shaft  at  Storm  King  mountain  on  the 
west  bank  to  another  shaft  on  the  cast  side  of  the  river  at  Breakneck  mountain,  a 
distance  of  3,022  feet. 


20 


SHANDAKEN  TUNNEL 


Joint  contains  about  280  lbs 
poured  lead  and  23  lbs.  of  colt 


32- f gib: 


lt*4‘  steel  band  shrunk  on 


FLEXIBLE^JOINTED  PIPE 
NARROWS  SIPHON 

For  City  conduits  of  Catskill  aqueduct 
standard  bell-and-spigot  cast-iron  pipes 
and  lock-bar  and  riveted  steel  pipes  were  used 


PRESSURE  TUNNEL 

Ronaout,  Wallkill. . - . . 14-6" 

Moodna . . . . 14'- 2” 

Hudson.  Breakneck  Croton  Lake. . l4'-0" 

Yonkers . . . . . . Iff-  7" 

city . . ...-j$-mo:imzo:ii'  o" 


REINFORCED  CONCRETE  AQUEDUCT 
KENSICO  BY-PASS 


-15-0'- 


-28-0' 


.  CUT-AND-COVER  AQUEDUCT  ,  , 

( Kensico  Reservoir  to  Hill  View  Reservoir  n'-6‘- 18-0'  / 


Standard  types  of  conduit  used  in  the  Catskill  aqueduct.  (In  addition  to  the  above, 
riveted  and  lock-bar  joint  steel  pipes  and  bell-and-spigot  cast-iron  pipes  of 
ordinary  types  were  used.) 


21 


The  construction  of  cut-and-cover  aqueduct.  In  the  foreground  the  concrete  invert,  or  bottom,  is  being  placed  and  immediately  back  of  it  are  the 
steel  inside  lorr.is,  followed  by  a  section  where  the  steel  outside  forms  also  have  been  plaeed  ready  to  receive  the  concrete,  brought  on  the 
railroad  and  lifted  into  place  by  the  locomotive  crane.  In  the  background  is  completed  aqueduct  ready  to  be  covered  with  earth  embankment. 


22 


Pressure  tunnel:  (1)  drilling  “heading”  and  “bench”;  (2)  loading  dynamite  into  the  holes; 
(3)  removing  the  “muck”;  (4)  hauling  “muck”  out  and  concrete  in;  (5)  placing  concrete 
lining  around  steel  forms;  and  (6)  grouting  crevices  in  the  rock  back  of  the  lining. 


23 


Across  the  smaller  valleys  or  where  the  rock  was  not  suitable  for  a  pressure 
tunnel,  riveted  steel  pipe  encased  in  concrete  and  lined  with  two  inches  of  cement 
mortar,  was  laid  in  a  trench  just  below  the  natural  surface  and  covered  with  a 
protective  grassed  embankment  of  earth.  This  is  known  as  the  steel-pipe  siphon 
type,  although  it  is  not  truly  a  siphon  but  rather  an  inverted  siphon.  The  pipes 
are  from  9  to  11  feet  in  diameter  and  are  made  of  steel  plates  from  7/16  inch  to 
inch  in  thickness,  riveted  together.  There  are  fourteen  of  these  siphons,  totaling 
6  miles.  Provision  has  been  made  at  the  junction  of  these  siphons  with  the  ad- 


Ilarlem  Railroad  steel-pipe  siphon,  looking  northward  toward  Sarles  tunnel.  The  Siphon 
Chamber  superstructures  are  of  vitrified  paving  brick  culls  with  cast  concrete-stone  trim¬ 
mings  and  reinforced-concrete  tile  roofs.  Note  the  steel  lowers  of  the  aqueduct  electric 
power  transmission-line. 


joining  aqueduct  for  three  pipes  which  will  eventually  be  required,  although  at 
present  only  one  pipe  has  been  completed. 

The  cut-and-cover  aqueduct  and  the  tunnels  are  more  than  big  enough  for 
railroad  trains  to  pass  through  them  with  ease.  The  Catskill  aqueduct  is  twice  as 
long  as  the  two  Croton  aqueducts  put  end  to  end.  The  water  which  the  Catskill 
aqueduct  can  carry  would  be  waist  deep  between  the  buildings  in  Fifth  Avenue’s 
fashionable  shopping  district,  if  flowing  at  a  comfortable  walking  speed.  The 
water  used  by  New  York  City  each  day  weighs  about  eight  times  as  much  as  its 
population. 


24 


The  City  Tunnel 

From  Hill  View  reservoir,  Catskill  water  is  delivered  into  the  five  boroughs 
"by  a  circular  tunnel  in  solid  rock  reducing  in  diameter  from  15  feet  to  14,  13,  12 
and  11  feet.  The  total  length  of  the  tunnel  is  18  miles.  From  two  terminal  shafts 
in  Brooklyn,  steel  and  cast-iron  pipe-lines  extend  into  Queens  and  Richmond, 
respectively.  A  36-inch,  flexible-jpinted,  cast-iron  pipe,  buried  in  a  trench  in  the 
harbor  bottom,  has  been  laid  across  the  Narrows  to  the'  Staten  Island  shore, 
whence  a  48-inch  cast-iron  pipe  extends  to  the  Silver  Lake  reservoir.  The  total 
length  of  this  delivery  system  is  over  34  miles.  The  tunnel  is  at  depths  of  2C0 
to  750  feet  below  the  street  surface,  thus  avoiding  interference  with  streets,  build¬ 
ings,  subways,  sewers  and  pipes.  These  depths  are  necessary,  also,  to  secure 


f-v«  i  <  i  in  1 1 


A  full-circle  panorama  of  New  York  City's  streets  around  Madison  Square  showing  Shaft  18 
and  a  portion  of  the  City  tunnel  in  the  rock  more  than  200  feet  beneath  the  surface. 
Madison  Square  Garden  tower,  the  Metropolitan  tower  and  the  Flatiron  Building  are 
easily  recognized  from  left  to  right. 


a  substantial  rock  covering  to  withstand  the  bursting  pressure  of  the  water  inside 
and  afford  the  requisite  watertightness.  The  waterway  of  the  tunnel  is  lined 
throughout  with  Portland  cement  concrete. 

The  City  tunnel,  which  is  the  longest  tunnel  in  the  world  for  carrying  water 
under  pressure,  or  for  any  other  purpose,  was  constructed  from  25  shafts,  includ¬ 
ing  the  Downtake  shaft  at  Hill  View  reservoir,  about  4.CC0  feet  apart,  located  in 
parks  and  other  places  where  they  interfered  very  little  with  traffic.  Through 
twenty-two  of  these  shafts  the  water  is  delivered  into  the  street  mains.  These 
connections  from  the  tunnel  to  the  mains  are  made  by  means  of  vertical  riveted 
steel  pipes  (called  risers)  embedded  in  concrete  in  the  upper  part  of  each  shaft 
and  lined  with  concrete  to  prevent  corrosion  inside.  Provision  is  made  for  un¬ 
watering  the  tunnel,  whenever  necessary,  for  inspection,  cleaning  or  repairs. 


26 


Unusual  features  in  connection  with  the  operation  of  the  tunnel  are  the  bronze 
riser  valves  in  the  shafts,  48  inches  and  72  inches  in  diameter,  and  the  section 
valves,  66  inches  in  diameter,  also  of  bronze.  The  former  are  located  about  100 
feet  below  the  top  of  sound  rock  and  are  designed  to  close  automatically  in  case 
of  an  important  break  in  the  valve-chamber  or  in  the  street  mains,  causing  an 
abnormally  large  flow  of  water.  They  can  also  be  closed  by  hand  from  within  the 
chambers  at  the  shaft  tops.  The  section  valves,  two  in  number,  are  located  across 
the  main  tunnel,  at  the  bottoms  of  Shafts  13  and  18,  and  permit  the  tunnel  to  be 
divided  into  parts  and  drained  in  sections  without  putting  it  entirely  out  of  com¬ 
mission. 

At  Shaft  3,  at  the  northerly  end  of  Jerome  Park  reservoir,  and  at  Shaft  10, 
in  St.  Nicholas  park,  connections  were  .made  to  the  Jerome  Park  reservoir  and 
the  Croton  aqueducts,  respectively.  Below  24th  street,  there  are  connections  at 
each  of  the  shafts,  except  Shaft  24,  to  the  high-pressure  fire  service,  with  elec¬ 
trically-operated  valves  at  the  shafts  controlled  from  the  fire  pumping-stations. 

The  cost  of  the  portions  of  the  Catskill  aqueduct  within  the  City  limits,  in¬ 
cluding  the  tunnel,  pipe-lines,  appurtenances  and  Silver  Lake  reservoir,  was 
$23,000,000. 


THE  SCHOHARIE  DEVELOPMENT 

The  Schoharie  development,  on  which  work  is  now  under  way,  bears  equal 
importance  with  the  Esopus,  inasmuch  as  each  will  be  called  upon  to  yield  up¬ 
wards  of  250  million  gallons  daily  to  supply  the  full  carrying  capacity,  500  million 
gallons  daily,  of  the  main  aqueduct. 

Schoharie  creek  lies  north  of  the  Esopus,  in  the  heart  and  higher  section  of 
the  Catskill  mountains.  The  new  Gilboa  dam  will  be  located  about  four  miles  north¬ 
east  from  the  Grand  Gorge  station  of  the  Ulster  and  Delaware  railroad,  and  access 
to  the  site  is  to  be  had  over  existing  highways.  Grand  Gorge  station  is  66  miles 
by  rail  from  Kingston  and  155  miles  from  New  York.  It  is  120  miles  in  an  air 
line  north  of  the  City  Hall  and  35  miles  west  of  the  Hudson  river.  The  southerly 
line  of  Albany  county  extended  westerly  would  pass  directly  through  the  Schoharie 
reservoir.  The  tributaries  have  their  source  at  elevations  of  nearly  2,0C0  feet  in 
the  localities  of  Hunter,  Windham,  Prattsville  and  Grand  Gorge  in  Greene,  Dela¬ 
ware  and  Schoharie  counties.  The  watershed  is  similar  in  character  to  the  Esopus, 
chiefly  steep  mountains  of  shale  and  sandstone,  which  are  covered  with  wild  for¬ 
est  growth.  These  streams  are  flashy,  there  being  large  freshets  in  the  spring 
with  very  little  flow  during  the  summer  months.  Because  of  this  steep  and  rocky 
character,  the  flow  in  the  streams  is  a  large  proportion  of  the  rainfall.  Of  the 
47  inches  depth  of  rainfall  in  a  year  on  the  Esopus  watershed,  29.5  inches  (63  per 
cent.)  appears  as  stream  flow,  while  the  Schoharie,  with  only  39.5  inches  of  rain¬ 
fall,  yields  27.2  inches  (69  per  cent.)  as  stream  flow.  Compared  with  these,  the 
Croton  yields  22.4  inches  of  stream  flow,  and  the  Wachusett  watershed  of  the  Bos¬ 
ton  supply  yields  but  21.3  inches  of  stream  flow  on  the  average. 

While  the  Esopus  flows  out  of  the  Catskills  through  the  southerly  gateway 
toward  Kingston  and  the  Hudson  river,  the  Schoharie  flows  out  through  the 
northerly  portals  to  the  Mohawk  river  near  Amsterdam.  It  lies  at  a  sufficiently 
high  elevation  to  enable  the  flow  to  be  intercepted  by  a  dam  at  Gilboa,  reversing 


27 


Sections  of  a  typical  shaft  and  chamber  of  the  City  tunnel,  with  details  of  a  riser 

valve  and  shaft  cap. 


28 


the  direction  and  sending  the  water  through  an  18-mile  tunnel  under  the  inter¬ 
vening  Shandaken  mountain  range  into  Esopus  creek  at  Allaben  in  Ulster  county.. 
The  water  thus  diverted  will  join  the  water  of  the  Esopus  and  find  its  way  for  15 
miles  into  the  Ashokan  reservoir,  where  it  will  be  available  for  the  main  Catskill’ 
aqueduct.  Thus  the  Catskill  system  is  extended  36  miles,  making  a  distance  of 
156  miles  from  the  Gilboa  dam  to  the  Silver  Lake  reservoir  on  Staten  Island. 

In  the  original  report  of  October  9,  1905,  it  was  contemplated  that  both  the 
Rondout  and  Schoharie  watersheds  would  be  developed  to  supplement  the.  Esopus, 
in  furnishing  the  desired  5C0  million  gallons  per  day.  Subsequent  borings  in  the 
Rondout  disclosed  such  subsurface  conditions  that  to  build  a  dam  there  would 
be  much  more  expensive  than  originally  anticipated.  On  the  other  hand  the  ac¬ 
cumulation  of  accurate  run-off  data  in  the  Catskill  region  has  adequately  proved 
that  the  safe  yield  of  the  Esopus  and  Schoharie  watersheds  is  higher  than  origin¬ 
ally  estimated.  So  that  by  placing  the  dam  at  Gilboa  instead  of  Prattsville  as 
originally  planned,  thus  increasing  the  watershed  from  226  square  miles  to  314 
square  miles,  and  also  increasing  storage  from  9l/z  to  20  billion  gallons,  the  Scho¬ 
harie  alone  can  be  depended  upon  for  250  million  gallons  per  day,  which  with  the- 
Esopus  will  yield  the  contemplated  500  million  gallons  daily. 

This  amended  plan  was  approved  by  the  Board  of  Estimate  and  Apportion¬ 
ment  January  31,  1916,  and  by  the  State  authorities  June  6,  1916.  The  land-taking 
surveys  were  begun  in  July,  1916,  and  detailed  subsurface  investigations  by  bor¬ 
ings  for  the  definite  location  and  design  of  the  tunnel  and  dam  were  prosecuted  in- 
1916  and  1917,  and  it  is  planned  that  the  entire  development  will  be  completed  in- 
1924. 


The  Shandaken  Tunnel 


Contract  200,  for  the  construction  of  the  Shandaken  tunnel,  was  awarded  on 
November  9,  1917,  for  $12,138,738. 

Ti  e  Intake  is  located  about  3/>  miles  north  of  the  Village  of  Prattsville. 
From  here  the  tunnel  extends  in  a  generally  southeasterly  direction  until  just 
south  of  the  Village  of  Allaben,  where  it  discharges  into  the  Esopus  creek.  The 
tunnel  is  horseshoe  in  section,  concrete  lined,  with  inside  dimensions  of  11  feet  6 
inches  in  hight  by  10  feet  3  inches  in  width,  and  provides  for  a  uniform  slope  of 
4.4  feet  per  mile  except  for  the  northerly  3J4  miles,  which  is  depressed,  making 
this  portion  a  pressure  tunnel.  Seven  intermediate  shafts  are  provided,  the  aggre¬ 
gate  depth  of  shaft  being  3,238  linear  feet,  the  maximum  depth  of  a  single  shaft 
being  639  feet.  The  minimum  distance  between  shafts  is  1.3  miles,  the  maximum 
2.7  miles.  All  shafts  are  circular  and  will  be  concrete  lined,  surmounted  with  shaft 
houses  built  of  native  stone.  The  upper  portion  of  the  Intake  shaft  will  be  so 
constructed  that  it  will  act  as  a  Venturi  meter  and  the  building  over  this  shaft 
will  also  contain  the  control  gates  and  the  keeper’s  residence. 

After  the  award  of  the  contract,  work  was  begun,  and  to  June  1,  1919,  there 
had  been  excavated  2,310  feet,  or  71  per  cent,  of  shaft,  and  63  per  cent,  of  the 
concrete  lining  in  the  shafts  had  been  placed. 

This  tunnel  construction  includes  about  600.000  cubic  yards  of  rock  excavation, 
100,000  cubic  yards  of  earth  excavation.  200,000  cubic  yards  of  concrete  masonry 
and  445,000  barrels  of  Portland  cement. 


29 


The  Gilboa  Dam 

Contract  203.  for  the  construction  of  Gilboa  dam.  was  advertised  and  bids 
were  opened  on  May  14,  1919;  all  bids  were  rejected  and  the  contract  is  now  being 
advertised,  the  bids  to  be  opened  on  June  19,  1919.  The  work  is  to  be  completed 
within  years  after  the  service  of  notice  to  begin  work,  or  approximately  at  the 
end  of  1924. 

The  construction  includes  about  396,000  cubic  yards  of  earth  excavation. 
92,500  cubic  yards  of  rock  excavation,  617.000  cubic  yards  of  refilling  and  em¬ 
banking,  436,000  cubic  yards  of  masonry  and  480,000  barrels  of  Portland  cement. 
The  dam  is  composed  of  two  parts — an  overfall  masonry  portion  about  1.300 
feet  in  length  and  having  a  maximum  hight  of  about  160  feet  with  the  crest  at 
Elevation  1,130  feet  above  sea-level,  and  an  earth  section  at  Elevation  1,150  feet, 
with  core-wall,  approximately  1.000  feet  long.  Along  the  down-stream  toe  of  the 
dam  there  is  to  be  constructed  a  channel  for  collecting  and  conveying  the  over¬ 
flow  flood  waters  into  the  present  channel  of  Schoharie  creek  below  the  dam. 

The  1,300-foot  overfall  portion  of  the  dam  will  be  constructed  of  cyclopean 
masonry,  being  large  blocks  of  stone  buried  in  concrete ;  the  water  side  will  be 
faced  with  natural  stone  down  as  far  as  the  water  will  he  drawn  ;  the  down-stream 
face  of  the  masonry  section  will  be  made  in  large  steps  from  10  to  20  feet  in  tread 
and  rise,  all  faced  with  natural  stone  with  the  overfall  corners  composed  of  the 
largest  possible  stones  set  on  edge,  thoroughly  anchored.  This  portion  is  founded 
on  solid  rock. 

The  1.000-foot  earth  section  for  the  left  or  west  bank  is  required  because  of 
the  pre-glacial  gorge,  which  swings  under  the  mountainside  ;  the  masonry  section, 
where  it  joins  the  earth  section  is  flanked  at  right  angles  both  up-stream  and 
down-stream  by  long,  high  and  heavy  retaining-walls,  faced  with  natural  stone; 
these  walls  will  intercept  the  long  earth  slopes  of  the  earth  section  ;  beyond  them 
the  masonry  section  of  the  dam  will  taper  into  a  core-wall  which  will  be  continuous 
throughout  the  length  of  the  earth  section  and  extend  into  the  mountainside;  the 
earth  section  in  places  will  extend  above  100  feet  in  hight  and  will  be  upwards 
of  400  feet  in  thickness  at  the  base;  the  water-side  slope  of  the  earth  embankment 
will  be  paved  with  heavy  stone. 

Tiie  Schoharie  Reservoir 

The  Schoharie  reservoir  will  serve  both  as  a  diverting  and  as  a  storage  reser¬ 
voir.  It  will  store  20  billion  gallons,  so  that  a  large  part  of  the  storage  for  the 
Schoharie  has  been  provided  in  the  Ashokan  reservoir.  It  holds  only  0.14  of  the 
amount  of  the  total  flow  of  the  Schoharie  for  an  average  year,  while  the  Ashokac 
holds  1.03  times  the  flow  of  Esopus  creek.  The  tunnel  was  therefore  built  large 
enough  so  that  in  times  of  plenty  the  water  can  be  rushed  through  to  Ashokan 
at  a  rate  of  600  million  gallons  a  day,  more  than  twice  the  normal  rate  of  con¬ 
templated  draft  from  Schoharie.  The .  Ashokan  and  Schoharie  reservoirs  com¬ 
bined  will  hold  0.53  of  the  combined  Schoharie  and  Esopus  yearly  flow,  while  if 
we  include  the  Kensico  reservoir  the  Catskill  system  will  have  available  storage 
of  177  billion  gallons,  or  0.62  of  the  average  yearly  flow  of  all  its  contributing 
streams. 

The  reservoir  is  approximately  five  miles  long  and  about  one  mile  in  maximum 
width,  reaching  from  Gilboa  to  Prattsville,  the  former  being  the  only  village  dis- 


3d 


31 


turbed.  No  railroad  will  be  disturbed,  and  the  highways  to  be  relocated  require 
12.4  miles  to  replace  13.6  miles  submerged.  As  at  Ashokan,  the  City  has  acquired 
a  marginal  strip  around  the  shore  line  for  sanitary  protection  of  the  water. 


CATSK1LL  WATER 

Catskill  water  is  a  surface-water  collected  in  a  thinly  populated  region  from 
hills  and  mountains  composed  entirely  of  shale  and  sandstone  rock.  Ihe  result 
is  a  water  exceedingly  soft  and  free  from  pollution.  It  is  very  much  softer  than 
the  ground-water  obtained  from  the  wells  of  Long  Island  and  also  superior  in  this 
respect  to  the  Croton  water.  Certain  steps  are  taken  to  safeguard  and  even 
improve  the  natural  excellent  quality  of  the  water. 

Marginal  strips  of  land  around  the  reservoirs  were  obtained  and  have  been 
to  a  large  extent  cleared  of  undesirable  growth  and  dead  wood  and  have  been 
reforested.  This  will  tend  to  prevent  erosion  of  the  shores  and  gives  such  control 
of  the  ground  adjacent  to  the  reservoirs  that  contamination  and  pollution  may  be 
avoided. 

Much  attention  has  been  paid  to  the  pollution  of  tributary  streams,  especially 
near  communities  where  there  is  a  considerable  influx  of  summer  visitors.  The 
cooperation  of  communities  has  been  obtained  and  tli£  sanitary  condition  of  hun¬ 
dreds  of  premises  has  been  improved,  resulting  not  only  in  local  benefit  but  also  in 
safeguarding  New  York  City’s  supply. 

Storage. — The  available  storage  of  water  when  the  three  large  reservoirs, 
Ashokan,  Schoharie  and  Kensico,  are  full,  is  177  billion  gallons.  The  result  of 
the  long  storage  which  the  water  receives  is  that  sedimentation,  bleaching  by 
the  sun,  oxidation  by  the  winds  and  sterilization  by  natural  processes  go  on  more 
or  less  continuously. 

The  temperature,  turbidity,  suspended  microscopic  growths  and  other  qual¬ 
ities  of  the  wrater  in  a  large  reservoir  vary  at  different  depths  and  at  different  sea¬ 
sons  of  the  year.  The  gate-houses  through  which  the  water  is  drawn  from  the 
reservoirs  into  the  aqueduct  are  so  arranged  that  the  water  may  be  drawn  from 
the  depth  furnishing  the  most  desirable  water.  Furthermore,  a  dividing  weir 
across  Ashokan  reservoir  makes  it  possible  to  draw  water  from  the  basin  fur¬ 
nishing  the  best  water  at  any  given  time. 

Temperature. — The  temperature  of  the  water  in  the  Ashokan  reservoir  durin* 
the  winter  months  is  quite  constant  at  all  depths.  The  surface-water  in  the  fall  is 
cooled  by  the  atmosphere,  and  as  it  becomes  colder  than  the  water  beneath  a 
vertical  circulation  takes  place  whereby  the  colder  and  heavier  wrater  goes  to  the 
bottom,  resulting  in  what  is  termed  a  turnover.  During  the  middle  of  winter  the 
general  temperature  is  as  low  as  33  degrees  Fahrenheit.  During  the  summer 
months,  however,  there  is  practically  no  vertical  circulation  when  the  upper  lay¬ 
ers  are  being  warmed  by  the  sun.  During  the  summer  the  water  at  the  bottom 
of  the  reservoir  reaches  a  temperature  of  about  60  degrees  Fahrenheit  while  the 
water  near  the  surface  generally  is  much  warmer. 

The  water  taken  into  the  aqueduct  after  aeration  at  Ashokan  has  an  average 
temperature  of  50  degrees  Fahrenheit  in  the  winter  being  as  low  as  33  degrees 
Fahrenheit  and  in  the  summer  never  reaching  over  68  degrees  Fahrenheit.  The 


■ 


32 


Ashokan  aerator  and  the  beginning  of  the  Catskill  aqueduct.  The  large  building  is  the  Screen  chamber,  at  which  the  Standard  aqueduct  begins. 
Following  the  aqueduct  embankment,  one  comes  first  to  the  Gaging  chamber  and,  to  the  left,  the  two  chambers  of  the  Esopus  steel-pipe  siphon. 
The  Lower  gate-chamber  is  just  out  of  the  picture  at  the  right. 


33 


water  as  it  passes  through  the  aqueduct  is  everywhere  in  a  closed  duct  and  is  not 
only  protected  from  interference  of  ice.  snow  and  pollution,  but  is  thoroughly  in¬ 
sulated  by  the  surrounding  concrete,  rock  and  earth.  Thus  it  is  that  in  the  length 
of  a  day,  which  is  the  time  which  it  takes  the  water  leaving  the  Ashokan  reservoir 
to  reach  the  City,  the  temperature  of  the  water  is  not  changed  while  it  is  in  the 
aqueduct.  The  water  flows  through  the  aqueduct  at  about  a  brisk  walking  speed, 
that  is,  from  three  to  four  miles  per  hour. 

Aeration. — Along  the  aqueduct,  just  below  Ashokan  and  Kensico  reservoirs, 
provision  has  been  made  for  jetting  the  water  into  the  air  in  line  spray,  thus 
permitting  thorough  admixture  of  oxygen  from  the  atmosphere  and  removal  of 
objectionable  gases  and  the  breaking  down  of  other  matters  causing  tastes  and 
odors.  The  two  aerators  are  substantially  alike  and  are  great  fountain  basins, 
approximately  500  feet  long  by  250  feet  wide,  each  containing  about  1,600  nozzles, 
through  which  jets  of  water  are  thrown  vertically  into  the  air. 

Removal  of  Turbidity. — At  a  number  of  places  in  the  Catskill  watersheds 
there  are  banks  of  very  fine  clay-like  earth  on  the  hill  slopes  or  along  the  streams 
and  margins  of  the  reservoirs.  Under  certain  conditions  of  storm  or  very  rapid 
run-off  of  water  some  of  this  earth  is  carried  into  the  streams  and  by  them  into 
the  reservoirs,  making  the  water  somewhat  turbid.  Most  of  this  material  causing 
the  turbidity  settles  in  the  reservoirs  during  the  period  of  storage,  but  at  very 
infrequent  intervals  some  of  the  most  finely  divided  particles  find  their  way  into 
the  aqueduct.  Provision  has  been  made  for  eliminating  when  necessary  the  re¬ 
maining  turbidity  by  a  coagulating  plant  located  about  two  miles  above  Kensico 
reservoir.  The  process  consists  of  the  introduction  into  the  water  of  very  small 
quantities  of  alum  or  sulphate  of  alumina.  It  reacts  with  the  minute  quantities  of 
lime  naturally  in  the  wTater,  forming  a  flakey  precipitate;  that  is,  it  forms  flakes 
resembling  unmelted  snow  flakes,  which  being  heavier  than  the  water,  completely 
settle  to  the  bottom  during  the  storage  period  in  Kensico  reservoir.  During  the 
settling  the  precipitate  intercepts  and  carries  down  with  it  the  finely  divided  par¬ 
ticles  held  in  suspension,  thus  completely  relieving  the  water  of  its  turbidity. 

Sterilization. — In  order  to  eliminate  the  very  small  proportion  of  pathogenic 
or  harmful  bacteria  which  may  occur  among  the  vastly  larger  proportion  of 
harmless  microscopic  life  found  in  the  wrater,  the  water  is  sterilized  by  the  intro¬ 
duction  of  chlorine,  a  very  active  oxidizing  agent.  This  takes  place  in  the  Screen 

chamber  after  the  water  drawn  from  Kensico  reservoir  has  been  aerated.  The 

chlorine,  normally  a  gas,  is  obtained,  compressed  to  a  liquid  state,  and  delivered 

to  the  point  of  use  in  containers  holding  100  pounds  each.  The  chlorine,  as  it 
is  released  from  the  containers,  reverts  to  the  gaseous  state  and  is  led  through 
control  and  measuring  devices,  and  dissolved  in  water.  The  resulting  solution  is 
fed  by  rubber  tubing  which  is  not  affected  by  the  corrosive  action,  to  various 
depths  of  the  water  in  the  aqueduct,  where  it  is  almost  instantly  disseminated. 
The  control  of  the  gas  through  the  chlorinating  apparatus  is  so  complete  that  only 
sufficient  gas  is  introduced  to  effect  the  desired  sterilization,  all  the  gas  being  taken 
up  by  reaction  on  the  organic  life  or  other  foreign  material  in  the  water. 

Filtration. — Provision  for  a  filtration  plant  was  made  by  the  acquisition  of  315 
acres  of  land  and  by  building  a  connection  chamber  to  the  aqueduct  about  two 
miles  below  Kensico  reservoir. 

Measurement. — Measurements  of  the  amount  of  rainfall  at  various  selected 
places  throughout  the  watersheds  and  the  flow  of  the  streams  are  made  by  stand- 


34 


One  of  the  Venturi  meters  in  the  Catskill  aqueduct. 


arc!  methods  for  the  purpose  of  determining  the  amount  of  water  available.  Be¬ 
sides  this  the  amount  of  water  passing  through  the  aqueduct  is  measured,  first  just 
after  its  entrance  from  Ashokan  reservoir,  then  before  entrance  into  Kensico  res¬ 
ervoir,  again  as  it  leaves  this  reservoir,  and  finally  upon  its  entrance  into  the  City 
tunnel  after  passing  through  Hill  View  reservoir.  These  measurements  are  made 
by  means  of  Venturi  meters  accurately  constructed  as  parts  of  the  aqueduct.  At 
these  points  the  aqueduct  is  circular  in  section  and  one  short  portion  is  built  with 
a  greatly  reduced  cross-section,  similar  to  the  contraction  of  an  hour  glass.  Ap- 


Feak  Gaging  chamber  in  the  Catskill  aqueduct  south  of  Peak  tunnel. 


paratus  attached  to  these  meters  is  so  designed  as  to  accurately  record  and  register 
the  amount  of  water  passing.  The  three  meters  installed  above  the  City  are  the 
largest  ever  constructed,  each  being  410  feet  long  and  built  of  reinforced  concrete. 
The  contracted  portion  consists  of  a  bronze  casting  and  is  7  feet  9  inches  in  diam¬ 
eter.  Provision  is  also  made  at  gaging  chambers  for  obtaining  the  velocity  of 
the  water  by  means  of  current  meters  lowered  into  the  aqueduct. 

EXPLORATIONS  AND  SURVEYS 

In  order  that  the  Catskill  aqueduct  might  be  most  safely  and  economically 
located,  extensive  surveys  and  subsurface  explorations  were  made  of  both  topo- 


36 


graphical  and  geological  character.  It  was  necessary  for  the  Board’s  engineers  to 
make  about  3,000  miles  of  line  surveys,  besides  the  very  extensive  topographical 
surveys  of  the  reservoir  sites  and  the  final  location  of  the  aqueduct. 

For  determining  the  exact  location  of  the  deep  valley  crossings,  geological 
explorations  by  means  of  borings  into  the  rock,  with  diamond  and  shot  drills,  were 
necessary,  and  were  carried  on  under  the  immediate  supervision  of  skilled,  prac¬ 
tical  geologists.  Such  explorations  were  also  made  for  the  locations  of  the  dams 
and  for  other  features  of  the  work.  In  the  aggregate,  these  borings  amounted  to 
240,000  feet,  or  45  miles. 

Before  the  Board  began  its  work  the  nature  of  the  Hudson  river  bed  from 
Albany  to  the  sea,  and  the  depth  of  the  bed-rock  beneath  it  were  matters  of  con¬ 
jecture.  Definite,  dependable  information  must  be  had;  therefore,  the  Board  be¬ 
gan  almost  immediately  after  preliminary  organization  of  its  Engineering  bureau, 
investigations  to  determine  where  the  river  could  be  crossed  safely  and  econom¬ 
ically.  A  number  of  possible  crossings  were  explored,  but  all  of  them  developed 
great  difficulties,  excepting  the  one  at  the  northerly  end  of  the  Highlands,  where 
a  band  of  granite  crosses  the  valley,  outcropping  in  Storm  King  mountain  on  the 
west  side  and  Breakneck  mountain  on  the  east  side.  Endeavors  were  made  by 
boring  from  scows  on  the  surface  of  the  river  to  determine  the  depth  to  the  bed¬ 
rock,  but  this  work  proved  tedious  and  expensive,  and  at  best  could  give  informa¬ 
tion  at  only  a  few  points.  Winds,  tides  and  traffic  and  the  severe  winter  weather 
all  militated  against  this  method  of  exploration.  It  was  therefore  determined  to 
start  a  test  shaft  on  each  bank  as  close  to  the  edge  of  the  river  as  was  practicable, 
and  when  a  suitable  depth  had  been  attained,  to  drill  from  a  chamber  in  the  side 
of  the  shaft  inclined  bore  holes  out  under  the  river.  From  each  shaft  two  holes 
were  drilled.  In  each  case  the  first  hole  was  inclined  rather  steeply  downward  so 
as  to  reach  the  center  of  the  valley  at  a  depth  about  1,500  feet  below  the  surface 
of  the  river.  The  holes  were  each  about  2,000  feet  long.  Many  interesting  diffi¬ 
culties  were  overcome  and  samples  of  the  rock  obtained  for  the  whole  distance. 
The  second  holes  were  then  driven  at  a  much  flatter  slope,  taking  the  chance  that 
they  might  possibly  run  out  of  the  rock  before  reaching  the  center  of  the  valley. 
These  two  holes,  however,  w^ere  wholly  in  rock  and  intersected  at  a  depth  of 
about  950  feet.  Meanwhile  a  drilling  from  a  scow  near  the  center  of  the  river 
had  reached  a  depth  of  768  feet  without  entering  the  bed-rock,  although  having 
developed  evidences  of  being  near  the  rock,  when  the  hole  was  lost  through  acci¬ 
dent.  With  this  information  in  hand  it  was  determined  to  locate  the  tunnel  across 
the  river  at  a  depth  of  1.114  feet  below  the  river  surface,  being  assured  that  at  the 
shallowest  place  it  would  have  somewhat  more  than  the  necessary  minimum  of 
150  feet  of  sound  rock  above  its  roof. 

Some  deep  and  difficult  drilling  was  required  also  in  connection  with  the  loca¬ 
tion  of  the  City  tunnel  and  its  shafts,  particularly  in  the  lower  east  side  of  Man¬ 
hattan  Island,  where  the  old  bed  of  the  East  River  was  crossed,  which  lies  west 
of  the  present  location  of  that  river. 

THE  COST 

For  surveys,  real  estate,  construction,  engineering  and  general  supervision,  and 
all  other  items  except  interest  on  the  bonds,  the  total  cost  of  the  completed  Catskill 
system  will  be  about  $177,000,000,  of  which  $22,000,000  is  for  the  Schoharie  works. 
To  January  1,  1919,  $139,800,000  had  been  expended. 


37 


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CROSS-SECTION  OF  HUDSON  RIVER  CROSSING, 
LOOKING  SOUTH.  TOWARD  WEST  POINT 


Board  of  Water  Supply  Forces 


P  JAll*  iUAAl  in  L  1V1  A  1 

Bureau  1919  Various  Dates 

Commissioners  . • .  3  3 

Administration  bureau  . 33  66 

Police  bureau  . 47  387 

Engineering  bureau  : 

Chief  Engineer  and  staff  . 8  13 

Headquarters  department  .  83  260 

Reservoir  department  .  95  236 

Northern  Aqueduct  department  .  2  630 

Southern  Aqueduct  department  .  16  318 

City  Aqueduct  department  .  73  209 

Total,  Engineering  bureau  . . .  277 

Total,  Board  of  Water  Supply  .  360 

Engineering  bureau;  maximum  force  at  any  one  time .  1,348 

Maximum  total  forces  of  the  Board  . .  1,757 


*  Including  57  employees  absent  on  Military  or  Naval  duty,  and  4  employees  on  civilian 
duties  connected  with  the  war 


Statistics  of  Ashokan,  Kensico  and  Schoharie  Reservoirs 


Ashokan  Kensico  *Sciioiiarie 


gallons 
gallons 
8,18U  acres  3.5  sip 
acres  7.0  sq. 


gallons 
gallons 
miles=2,2l8  acres 
miles  =  4,500  acres  3.72 

370  feet 
4  miles 
30  miles 


38,000,000,000 

29,000,000,000 


Capacity,  total  . 

Capacity,  available... 

Water  surface . 

Land  acquired . 

Elevation  of  top  of 
dam,  above  tide  .  . 
Length  of  reservoir. 
Length  of  shore  line. 
Length  of  dams  and 

dikes  . 

Main  dam : 

total  length  . 

length  of  masonry 
portion  . 

bight  (maximum) . 
thickness  at  base 
(maximum)  .... 
thickness  at  top 
(minimum)  .... 
Width  of  reservoir: 

maximum  . 

average  . 

Depth  of  reservoir  : 

maximum  . 

average  . 

Villages  submerged  . 
Permanent  population 
of  submerged  area  at 
beginning  of  work. 
Cemeteries  removed. 
Bodies  reinterred .... 
Railroad  relocated  . . 
Highways  dis'con- 

tinued  . 

Highways  built  .... 
Highway  bridges  built 
Earth  and  rock  exca¬ 
vation  . 

Embankment  . 

Masonry  . 

Cement  . 

Maximum  number  of 
men  employed  .... 


1 30, GOO, 000, 000 
128,000,000,000 

12.8  sq.  miles~ 

23.8  sq.  miles=15,222 

610  feet 
12  miles 
40  miles 

5J4  miles 

4,650  feet 

1,000  feet 

252  feet 

190  feet 

23  feet 

3  miles 
1  mile 

190  feet 
50  feet 


2,000 
32 

2,800 

11  miles 

64  miles 
40  miles 
10 

2,500,000  cubic  yards 
7,300,000  cubic  yards 
900,000  cubic  yards 
1,200,000  barrels 

3,000 


3,300  feet 

1,825  feet 

1,825  feet 

307  feet 

235  feet 

28  feet 

3  miles 
1  mile 

155  feet 
52  feet 

1 


500 

none 

none 

none 

14.8  miles 
15.1  miles 
4 

1,400,000  cubic  yards 
2,010,000  cubic  yards 
965,000  cubic  yards 
897,000  barrels 

1,500 


22,000,000,000  gallons 
20,000,000,000  gallons 
1.83  sq.  miles=  1.170  acres 
sq.  miles=2, 372  acres 

1,130  feet 
5  miles 
12  miles 

2,300  feet 

2.300  feet 

1.300  feet  (Earth, 
1,000  feet) 

160  feet 

165  feet 

15  feet 

4/5  mile 
2/5  mile 

140  feet 
58  feet 
1 


350 

7 

1,330 

none 

13.6  miles 
12.4  miles 
2 

488,500  cubic  yards 
617,000  cubic  yards 
436,000  cubic  yards 
480,000  barrels 


Construction  not  yet  begun 


39 


Land  Acquired 

Acres  Square  Miles 


Schoharie  reservoir  .  2,372  3.7 

Shandakcn  tunnel .  80  .1 

Ashokan  reservoir  .  15,222  23.8 

Kensico  reservoir  .  4,5C0  7.0 

Aqueduct,  Ashokan  to  City  line  . 2,279  3.6 

Filter  site .  315  .5 

Hill  View  reservoir  .  164  .2 

Silver  Lake  reservoir  and  City  tunnel  .  166  .3 


Total  .  25,098  39.2 


